There has been increased concern over the problem of cleaning and filtering air in order to remove dust, pollen, smoke and other airborne impurities. It has been known to provide devices for the purpose of cleaning and filtering air in residential and commercial spaces to improve the quality of air breathed by inhabitants or users of such spaces.
In buildings having central air-conditioning systems, porous foam, fiberous material such as fiberglass and other materials, have been employed to filter air and these materials to some extent reduce the interior pollution. It has also been known to provide air-filtering means in connection with cooling fans and particularly with ceiling fans which seems to be more effective than fiberglass air filters of air-conditioning systems.
One example of the method and device for reducing the pollution of the air in a room equipped with a ceiling fan is shown in U.S. Pat. No. 4,676,721. As described therein, the ceiling fan has rotating blades covered with porous-dust absorbing fabric covers fitted onto the blades.
Another example is described in U.S. Pat. No. 4,422,824 which relates to a structure of a fan blade for use with a ceiling fan, which among other features, includes filtering pads preferably made of a plastic foam. The pads are located at the leading and trailing edges of the air space between the top and bottom of a hollow blade for the absorption of smoke and other impurities when the air passes through the area close to the ceiling fan location.
There is, however, still a need in the art to provide a simple and inexpensive air filtering system with increased air cleaning efficiency that could be used with different standard ceiling fans already in existence on the market.